Young's Double Slit Experiment

Young's double slit experiment is a classic experiment in the field of optics that demonstrates the wave nature of light. In this experiment, a beam of light is passed through a small slit and then split into two beams by passing through two closely spaced parallel slits. These two beams then interfere with each other, creating a pattern of bright and dark fringes on a screen placed behind the slits.

Intensity of Central Bright Band

The interference pattern produced by the double slit experiment consists of a series of bright and dark fringes. The central bright fringe is the brightest of all the fringes and is located at the center of the screen. The intensity of the central bright band is given by the formula:

I = I1 + I2 + 2(I1I2)1/2cosθ

where I1 and I2 are the intensities of the two interfering waves, and θ is the angle between them.

When the two waves are in phase, θ = 0 and the intensity of the central bright band is given by:

I = 2I1

This means that the intensity of the central bright band is twice the intensity of each individual wave.

When the two waves are out of phase, θ = π and the intensity of the central bright band is given by:

I = 2I2

This means that the intensity of the central bright band is twice the intensity of each individual wave.

When the two waves are partially in phase and partially out of phase, θ is some intermediate value and the intensity of the central bright band is given by:

I = 4I1I2/(I1 + I2)2

This means that the intensity of the central bright band is four times the intensity of each individual wave.